8.1. Suppose that (1, K2) has bivariate normal probability density function / ( y i , y2),...

8.1. Suppose that (1º, K2) has bivariate normal probability density function

/ ( y i , y2), with E(Y{) = ì, Å(Õ2) = ì + Á, Var(y,) = Var(y2) - ó2, and Corr(r,, Y2) = p. Show that f(yu y2)//(y2, yi) has form 8y''y2 for some constant S. Thus, under the assumption of an underlying bivariate normal distribution, explain why the ordinal quasi-symmetry model (8.7)

may be appropriate for a square ordinal table.